Hearing loss affects 15-26% of the world's population and among the elderly is the most common neurological disability. Although the relative contributions of hereditary and environmental factors to age- related hearing loss are unknown, the majority of inherited late-onset deafness is autosomal dominant and non-syndromic (autosomal dominant non-syndromic hearing loss, ADNSHL). The long-term goals of our research are: a) to identify ADNSHL-causing genes to address gaps in our understanding of the molecular biology of hearing and deafness in the elderly; and, b) to explore novel habilitation options for hearing loss. During the prior granting period, we focused on specific aims to: 1) localize and clone genes that cause ADNSHL; 2) expand phenotype-genotype studies to facilitate gene identification in small families; and 3) initiate experiments on RNA interference (RNAi) as a potential treatment for select types of hearing loss. In this competitive renewal, we will build on our past accomplishments by completing the following specific aims: Specific Aim 1: To identify novel deafness-causing genes in a cohort of 230 families segregating ADNSHL by using targeted sequence capture platforms and/or whole exome analysis followed by massively parallel sequencing and data analysis using a customized local deployment of the Galaxy bioinformatics web platform Specific Aim 2: To improve and validate the efficacy of RNAi as a therapeutic for the prevention of ADNSHL by: a) modifying the design of short hairpin RNA (shRNA) and artificial microRNA (miRNA) to enhance their potency in the Kcnq4+/dn mouse; and, b) testing RNAi in a second murine model of ADNSHL, the Tmc1 G411R mutant mouse The successful completion of these aims will have a major impact on our understanding of the biology of hearing and deafness and potentially on the treatment of some types of hearing loss.